U.S. Army Corps of Engineers New Orleans, Louisiana, United States

Adding value through innovation to protect the people of New Orleans from 100-year floods

civil constructors seabrook gates complex aerial view

Building massive floodgates to protect New Orleans

To protect the city of New Orleans from future hurricane and flood damage following Hurricane Katrina, the U.S. Army Corps of Engineers (USACE) engaged Alberici to construct the Seabrook Gate Complex across the Inner Harbor Navigational Canal.

civil constructors seabrook gates complex exterior

Super-sized structures

The massive flood control complex features a 440-ton sector gate consisting of two steel leaves that swing horizontally and close the 95-foot-wide navigational canal. On either side of the sector gate there is a 135-ton vertical lift gate. Alberici self-performed fabrication of each gate at our St. Louis-based facility, where they were then shipped to New Orleans on barges from Alberici’s port facility on the Mississippi River.

civil constructors seabrook gates complex work site

Innovation through collaboration

Working under an Early Contractor Involvement contract, Alberici performed extensive preconstruction services and engaged in formal partnering sessions with USACE and the designer of record. This effort helped to conceptualize several accepted innovations that reduced risks and project costs to the government, including the use of a temporary rock dike across the canal to reduce tidal flow during construction. This ultimately permitted the use of barge-mounted cranes to set the steel gates and drive steel pilings in the canal to build a cofferdam.

civil constructors seabrook gates complex aerial shot

Substantial savings delivered under an aggressive schedule

Alberici’s innovations resulted in a 9 percent total cost reduction from the initial estimate, a three-month schedule reduction from the project’s critical path, and provided temporary flood protection during construction that allowed USACE to achieve their congressionally-mandated milestone requirement for 100-year perimeter flood protection.